AO Smith 9007666005 Remote Temperature Controller 4" Universal Appliance Adaptor with Back-Flow Preventer For Takagi, Paloma, Rheem, Noritz tankless water heaters This Universal Adaptor has seals on both ends and has a back-flow preventer built in Can be used with 110 indoor non-condensing Can be used with 110 outdoor non-condensing Can be used with 310 indoor non-condensing Can be used with 310 outdoor non-condensing